starter motor keeps burning out

[mafya]

Hello everyone, just joined today due to having problems on my first ever mercedes!
I have a 2003 w211 Mercedes e270cdi Auto elegance in tealite blue with 146000 miles under its belt.
Everything was fine until last month when the starter motor failed on me, I had it replaced by Europa mercedes in Sheffield and a week later it failed again. Europa replaced the starter again and then it went again a week later. To cut a long story short the 3rd replacement starter has gone again today 5 days after being fitted and i'm at my wits end.
Can anyone shed any light on why this may be happening please?

 

[trapperjohn]

Welcome to the forum and sorry for your troubles.

Not heard of this before, others will be along soon to help you out I'm sure.

 

[dog68]

Maybe your alternator is pushing to many volts, get an auto electrician to do some checks.

 

[bolide]

Why did the first one fail? If the dealer has been replacing parts without finding the problem - and your experience suggests they may have done - then they need to locate the problem and not just cure the symptoms

I can't see what relevance the alternator has to this

Nick Froome
the independent Mercedes Estate specialists

 

[Druk]

Electrical or mechanical fault? Will the starter simply not spin, or is it spinning and the engine isn't turning?

 

[horgantrevor]

they should have found why it went also what make did they use and was it a recon starter or new make sure

also you have a electrical fault if new one was used bad earth or shorting out wire some were also alternator is producing over voltage check voltage of car when off then bump start the car if you can and check voltage again if over 14.5 volts you have a faulty alternator

sill they should have done all this when the first one went

ps ; is the starter disengaging also one car is started

 

[grober]

I would be looking at the engine earth strap first.
Can also be a fault with the ignition switch or associated circuitry where the starter remains "powered" after the key returns to the run position from the start position.

 

[Mercsys]

The starter and alternator don’t run at the same time (normally) and the starter current will drop the battery voltage significantly when cranking anyhow.
Does the engine start normally, my E320cdi is running in <3 seconds, and only one cranking cycle? Was the starter replaced OEM, or rebuilt?
A burnt-out motor suggests heavy current i.e. under load, and time to heat up. If it was a real motor burn out.
Did the motor stop working while attempting starting the engine, or didn’t work when attempting a new engine start?
You will usually know about it if the starter remains engaged, it is not pretty.

 

[mafya]

Thank you for replying, when the starter fails it goes to turn over then it sticks and all the dash display freezes up and throws up the esp and brake workshop lights and after that it doesn't even click or turn over. It does this every time it it fails.
I can't bump the car due to it being an automatic. The last time the starter went i told the dealer to check everything else to see if anything else is causing it to fail and they said everything else was fine.
When i got the car it had a 71ma battery on it which i changed for a Bosch silverline 100ma one from halfords and about 2 weeks later the first starter motor went. Could this be causing the problem although it is the recommended battery for the car?
I will be taking it back to Europa tommorrow and leaving it with them and asking them to check all leads and connections although i did ask them to on my last visit.
Thanks once again for the replies so far.
The starter should be a new unit as i was charged £285 just for the starter.

 

[mafya]

starter does not spin or click at all

 

[mafya]

they should have found why it went also what make did they use and was it a recon starter or new make sure

also you have a electrical fault if new one was used bad earth or shorting out wire some were also alternator is producing over voltage check voltage of car when off then bump start the car if you can and check voltage again if over 14.5 volts you have a faulty alternator

sill they should have done all this when the first one went

ps ; is the starter disengaging also one car is started

When the car does start it runs normally and i can't hear the starter still running.

 

[mafya]

The starter and alternator don’t run at the same time (normally) and the starter current will drop the battery voltage significantly when cranking anyhow.
Does the engine start normally, my E320cdi is running in <3 seconds, and only one cranking cycle? Was the starter replaced OEM, or rebuilt?
A burnt-out motor suggests heavy current i.e. under load, and time to heat up. If it was a real motor burn out.
Did the motor stop working while attempting starting the engine, or didn’t work when attempting a new engine start?
You will usually know about it if the starter remains engaged, it is not pretty.

The starter stopped working while attempting to start the car after an overnight rest, it just went to start and just froze/stuck, then nothing after that.

 

[dog68]

Time to put it on star, will save you money in the long run.

 

[mafya]

Time to put it on star, will save you money in the long run.

I have called the AA out and they have booked it in to be recovered to Europa tommorow, will tell them to put it on the star machine. Thanks for your reply.

 

[horgantrevor]

star is the best bet now getting silly if they said they checked every thing they didnt as they must have not done a star test

 

[Mercsys]

...it seems like the starter is able to draw enough current to burn it self out but not enough grunt to crank and start the engine, I would have thought the cranking sequence would have detected this, unless this drop in voltage also knocks out the logic (all the dash display freezes up and throws up the esp and brake workshop lights…), so look at the heavy currant cables to and from the battery and the earth straps as mentioned by grober in #7. I very much doubt the up rated battery is the cause, my E320 has a HIGH-CAPACITY BATTERY, and it is enormous.

Possibly there is a bazaar underlying problem where the engine is too stiff to be cranked, a torque converter problem perhaps, or head gasket allowing coolant or oil into the combustion chamber, causing a hydraulic lock. But probably a heavy cable is acting as a resistor triggering this cascade ending in the burnout.

I’d be interested to now the out come.

 

[autopian]

as an auto electrician - mechanic there are a few things that could cause this some of which may have already been mentioned.

you have a faulty ignition switch which is engaging the motor whilst being driven. this would make the engine seem noisier than usual but with the sound insulation and starter position you may not hear it, this would burn out the motor.

the teeth on the ring gear have burs which keep the starter engaged again burning out the motor.

a faulty battery, this would increase the current draw of the starter and blow it as would a faulty earth or battery supply. testing the battery and volt dropping earths and feeds would confirm a fault here.

a tight engine that is a partially seized pulley on one of the ancillary s on the front of the engine causing excessive current draw much like having a faulty battery or feed. I've seen a seized alternator do this so have them measure current draw with the drive belt disconnected.

its highly unlikely they are supplying faulty starter motors so must be a fault with your vehicle.

good luck
Chris

 

[mafya]

as an auto electrician - mechanic there are a few things that could cause this some of which may have already been mentioned.

you have a faulty ignition switch which is engaging the motor whilst being driven. this would make the engine seem noisier than usual but with the sound insulation and starter position you may not hear it, this would burn out the motor.

the teeth on the ring gear have burs which keep the starter engaged again burning out the motor.

a faulty battery, this would increase the current draw of the starter and blow it as would a faulty earth or battery supply. testing the battery and volt dropping earths and feeds would confirm a fault here.

a tight engine that is a partially seized pulley on one of the ancillary s on the front of the engine causing excessive current draw much like having a faulty battery or feed. I've seen a seized alternator do this so have them measure current draw with the drive belt disconnected.

its highly unlikely they are supplying faulty starter motors so must be a fault with your vehicle.

good luck
Chris

Your post is quite helpful and i will be mentioning the points raised with Europa tommorrow.

Thank you. Billy

 

[Ted]

Some good points by autoplan, but I would also add

If the starter is staying engaged, there should be a clutch on the pinion assembly.
The armature on the starter would also have destroyed itself
you would hear the starter spinning as it is turning at many times the engine speed

A couple of other things
It is not the alternator voltage
It is not a bad earth

You say the starter is burning out - what is the evidence for this? Have the old starters been tested/stripped and analysed? - this would give some clue to the problem.

Having said that, I'm sorry, I can't be much help, other than it looks like a fault (eis?) on the car is giving symptoms of starter failure, and your repairer hasn't diagnosed the problem correctly.

Test/stripdown of one or more of the 'failed' starters is the next thing imho. Plus as has been said, put it onto a star machine.

 

[Frankie]

This is all above my head a little. Doesn't the alternator only run when the engine is running? I'm confused